In general, a wireless communication system includes a mobile terminal and a base station (BS). The mobile terminal and the BS may transmit/receive information related to a channel state in order to improve performance in terms of throughput or goodput. For example, a mobile terminal and a BS in an IEEE (Institute of Electrical and Electronics Engineers) 802.16m system or 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) system may transmit and receive information regarding a channel state. Types of information regarding a channel state are not limited, and, for example, a CQI (Channel Quality Indicator), a PMI (Pre-Coding Matrix Index), an MCS (Modulation & Coding Scheme), sounding, and information regarding MIMO (e.g., a MIMO rate or rank) may be information regarding a channel state.